Device for supplying slurry for semiconductor, provided with pipe clogging prevention means

ABSTRACT

Disclosed is a device for supplying slurry for semiconductor in a polishing process when the semiconductor is manufactured. The slurry supply apparatus includes: a storage tank in which the slurry is stored; a plurality of pressure vessels connected to the storage tank, respectively, for receiving the slurry from the storage tank and discharging the slurry to the outside; an aspiration unit connected to the pressure vessels, for generating a vacuum pressure in the pressure vessels; and a centrifugal separation unit installed in a connection line of the aspiration unit between the pressure vessels and the aspiration unit, for separating foreign substances contained in the introduced compressed air from the compressed air by using a centrifugal force.

TECHNICAL FIELD

The present invention relates to a device for supplying slurry for semiconductor provided with pipe clogging prevention means and more particularly, to the device for supplying slurry for semiconductor provided with pipe clogging prevention means by which an orifice region or a pipe of an aspirator of the device for supplying slurry for semiconductor can be prevented from being clogged as slurry liquid is introduced into and stuck to an interior of the aspirator.

BACKGROUND ART

In general, a process technology for manufacturing a semiconductor device requires high integration and high concentration of semiconductor devices. Accordingly, a fine pattern forming technology should be applied.

Meanwhile, as a multilayered structure for wires is required, a surface structure of a semiconductor device is becoming complex and steps of interlayer films are becoming more severe. However, the steps of the interlayer films generated in this way cause a process defect, which should be removed.

Planarization technologies for solving the problem according to the related art include SOG, etch back, boron phosphorus silicate glass (BPSG), a reflow process, and a chemical/mechanical polishing (CMP) process. Among them, CMP processes are recently frequently used, and such a CMP process corresponds to a single process in which a chemical polishing process and a mechanical polishing process are combined to planarize a surface of a wafer which becomes larger as a diameter of a wafer becomes larger. The CMP process is a process of attaching a surface of a wafer having a step on a polishing pad, injecting an abrasive between the wafer and the polishing pad, and planarizing the wafer, and is suitable for a planarization process of a large diameter wafer.

A solution containing polishing abrasive particles and a chemical additive is used as an abrasive for the CMP process, and is called slurry. A chemical/mechanical planarization process is performed on a semiconductor wafer by using liquid slurry. Then, sizes of granules of the suspended solid particles of the slurry liquid applied for mechanical polishing should be sorted in a predetermined range to be supplied to CMP equipment. The reason is that if large particles of a predetermined size or more (for example, generally 1μ or more in the case of oxide slurry) are used in a CMP process, fine pattern damage may be caused on a semiconductor wafer, resulting in a defect in the semiconductor wafer.

Further, in order to use slurry in CMP process equipment, a separate slurry supply apparatus is provided to sort and supply particles suitable for the process characteristics are provided. The slurry supply apparatus supplies a proper amount of mixed solution in which an additive is mixed and diluted to correspond to raw slurry liquid and process characteristics used in the CMP process to the CMP apparatus.

Generally, in this case, the slurry is fed to a point of user (POU) while being maintained in a more static state so that a phenomenon of lumping the slurry can be maximally prevented.

To this end, a pressure vessel, an aspirator for suctioning slurry into the pressure vessel, and a N₂ gas supply unit for generating pressure and feeding a N₂ gas. Here, Bernoulli theorem is applied when slurry is filled in the pressure vessel. In detail, if the aspirator generates a negative pressure, a negative pressure (vacuum pressure) is generated in the pressure vessel through a negative pressure of the aspirator, and slurry is introduced into the pressure vessel and a predetermined amount of slurry is filled in the pressure vessel.

Then, the slurry filled in the pressure vessel is often suctioned into the aspirator in the form of droplets at an apex of suction. This is a phenomenon in which very small droplets of slurry spatter from the pressure vessel to be suctioned into the aspirator, and the slurry liquid suctioned then is accumulated as the process proceeds, and if the slurry liquid is dried in this state, it is stuck in a solid slurry state. Then, the solid slurry clogs an orifice of the aspirator, disturbs generation of a vacuum, and stops an operation of equipment, causing a process loss.

Further, when the slurry liquid overflows an exhaustion side of the vacuum generator and is accumulated, it may cause a severe loss to the equipment itself.

DETAILED DESCRIPTION OF THE INVENTION Technical Problem

Therefore, the present invention has been made in view of the above-mentioned problems, and an aspect of the present invention is to provide a device for supplying slurry for semiconductor provided with a pipe clogging prevention means by which an orifice region or a pipe of an aspirator of the device for supplying slurry for semiconductor can be prevented from being clogged as slurry liquid is introduced into and stuck to an interior of the aspirator.

Technical Solution

In accordance with an aspect of the present invention, there is a device for supplying slurry for semiconductor provided with pipe clogging prevention means in a polishing process when the semiconductor is manufactured, the device comprising: a storage tank in which the slurry is stored; a plurality of pressure vessels connected to the storage tank, respectively, for receiving the slurry from the storage tank and discharging the slurry to the outside; an aspiration unit connected to the pressure vessels, for generating a vacuum pressure in the pressure vessels; and a centrifugal separation unit installed in a connection line of the aspiration unit between the pressure vessels and the aspiration unit, for separating foreign substances contained in the introduced compressed air from the compressed air by using a centrifugal force.

The centrifugal separation unit may correspond to a cylindrical tubular body in which a suction port connected to the pressure vessels is formed on a side surface thereof and an exhaust port is formed perpendicular to the suction port such that the compressed air introduced into the suction port forms vortices in the tubular body to separate heavy slurry from the compressed air by using a centrifugal force.

The tubular body may be formed such that a diameter thereof becomes smaller downward, and a slurry storage box for storing the centrifugally separated slurry is provided at a lower portion of the tubular body.

Advantageous Effects

According to the present invention, slurry contained in introduced compressed air is centrifugally separated by installing a centrifugal separator in a device for supplying slurry for semiconductor and an aspiration unit so that only pure compressed air can be introduced into the aspiration unit, whereby a clogging phenomenon due to introduction of slurry liquid can be prevented and an equipment loss or a process loss can be prevented in advance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing a device for supplying slurry for semiconductor provided with pipe clogging prevention means according to an embodiment of the present invention;

FIG. 2 is an exemplary view showing an aspirator of the device for supplying slurry for semiconductor provided with pipe clogging prevention means according to the embodiment of the present invention;

FIG. 3 is a plan view showing a centrifugal separation unit of the device for supplying slurry for semiconductor provided with pipe clogging prevention means according to the embodiment of the present invention; and

FIG. 4 is a side view showing the centrifugal separation unit of the device for supplying slurry for semiconductor provided with pipe clogging prevention means according to the embodiment of the present invention.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing a device for supplying slurry for semiconductor provided with pipe clogging prevention means according to an embodiment of the present invention. FIG. 2 is an exemplary view showing an aspirator of the device for supplying slurry for semiconductor provided with pipe clogging prevention means according to the embodiment of the present invention.

As shown in FIG. 1, the device for supplying slurry for semiconductor provided with pipe clogging prevention means according to the present invention includes a storage tank 10, pressure vessels 21 and 22, an aspiration unit 30, and a centrifugal separation unit 40.

A plurality of pressure vessels 21 and 22 may be provided to be connected to the storage tank 10 in parallel to receive slurry and discharge the slurry to a point of user (POU).

Then, the slurry is provided to the pressure vessels 21 and 22 by a vacuum pressure (negative pressure) provided from the aspiration unit 30. That is, the aspiration unit 30 is connected to the pressure vessels 21 and 22 through pipes, respectively to apply a vacuum pressure to the interiors of the pressure vessels 21 and 22. Accordingly, the slurry in the storage tank 10 connected to the pipes of the pressure vessels 21 and 22 may be introduced into the pressure vessels 21 and 22 by the vacuum pressure. Then, a N₂ gas or a natural gas may be applied as a compressed gas (vacuum pressure forming gas) applied to the aspiration unit 30

As shown in FIG. 2, the aspiration unit 30 may be configured such that a nozzle 32 and a diffuser 33 are coupled to opposite sides of a vacuum port 31. Then, an orifice 36 is formed between the nozzle 32 and the diffuser 33 so that a N₂ gas supplied through a supply passage 35 is exhausted through a discharge passage 34 of the diffuser 33, and a flow of gas introduced into an entry of the discharge passage 34 (generated due to a difference between pressures of the orifice region and the exit of the discharge passage: a Venturi effect) is generated in the vacuum port 31 by the orifice 36 to generate a negative pressure in the vacuum port 31. Accordingly, a vacuum pressure may be generated in the pressure vessels 21 and 22 communicated with an inlet passage 37.

Meanwhile, if a vacuum pressure is generated in the pressure vessels 21 and 22, slurry liquid is often introduced into the vacuum port 31 in the process of supplying slurry into the pressure vessels 21 and 22. A centrifugal separation unit 40 is additionally provided in the present invention to prevent slurry particles from being introduced through the vacuum port 31 and stuck to the orifice 36 or the discharge passage 34.

FIG. 3 is a plan view showing a centrifugal separation unit of the device for supplying slurry for semiconductor provided with pipe clogging prevention means according to the embodiment of the present invention. FIG. 4 is a side view showing the centrifugal separation unit of the device for supplying slurry for semiconductor provided with pipe clogging prevention means according to the embodiment of the present invention.

As shown in FIGS. 3 and 4, the centrifugal separation unit 40 may be configured such that a slurry storage box 42 is provided in a cylindrical tubular body 46. Then, a suction port 43 is formed on a side surface of the tubular body 46 and an exhaust port 44 is formed at an upper portion of the tubular body 46 to be perpendicular to the suction port 43. The suction port 43 is connected to the pressure vessels 21 and 22, respectively, and the exhaust port 44 is connected to the aspiration unit 30.

The tubular body 46 may become narrower toward a lower end 41 thereof so that an inclined surface 45 is formed on an inner peripheral surface thereof. Accordingly, as a width of the tubular body 46 becomes narrower downward, rotational acceleration of vortices can be increased along the inclined surface 45 when the vortices are generated. Of course, the tubular body 46 may be formed to have a cylindrical shape whose diameters are the same at upper and lower sides thereof

The slurry storage box 42 is connected to a lower end 41 of the tubular body 46, so that as the slurry separated by the centrifugal force is lowered due to gravity and stored finally. Then, the slurry storage box 42 may be attached to and detached from the tubular body 46 to conveniently process the stored slurry.

In a description of an operation of the above-configured centrifugal separation unit 40, first, if slurry is introduced through the suction port 43 together with compressed air, vortices (having a cyclone shape) are generated along an inner peripheral surface of the tubular body 46 and the compressed air is withdrawn through the exhaust port 44. As shown in FIG. 3, as the suction port 43 is installed at a periphery of a side surface of the tubular body 46 and the suction port 43 and the exhaust port 44 are disposed perpendicular to each other, the compressed air suctioned into the cylindrical tubular body 46 is accelerated along an inner peripheral surface of the tubular body 46 and is exhausted through the exhaust port 44 while generating vortices.

If the compressed air introduced into the tubular body 46 is swirled, the relatively heavy slurry is pushed to the outside by a centrifugal force. Then, the slurry is rotated along the inclined surface 45 of the tubular body 46, and is further rotated and lowered to the lower end 41 of the tubular body 46 due to its weight and is finally stored in the slurry storage box 42.

Meanwhile, the pure compressed air (the compressed air by which the slurry is separated) is concentrated to a center of the tubular body 46 and is introduced into the aspiration unit 30 through the exhaust port 44. Then, since the compressed air exhausted through the exhaust port 44 is pure compressed air which does not have sludge, the slurry is prevented from being introduced into and stuck to the aspiration unit 30, causing a clogging phenomenon.

While the invention has been described in connection with various aspects, it will be understood that the invention is capable of further modifications. This application is intended to cover any variations, uses or adaptation of the invention following, in general, the principles of the invention, and including such departures from the present disclosure as come within the known and customary practice within the art to which the invention pertains. 

1. A device for supplying slurry for semiconductor in a polishing process when the semiconductor is manufactured, the device comprising: a storage tank in which the slurry is stored; a plurality of pressure vessels connected to the storage tank, respectively, for receiving the slurry from the storage tank and discharging the slurry to the outside; an aspiration unit connected to the pressure vessels, for generating a vacuum pressure in the pressure vessels; and a centrifugal separation unit installed in a connection line of the aspiration unit between the pressure vessels and the aspiration unit, for separating foreign substances contained in the introduced compressed air from the compressed air by using a centrifugal force.
 2. The device of claim 1, wherein the centrifugal separation unit corresponds to a cylindrical tubular body in which a suction port connected to the pressure vessels is formed on a side surface thereof and an exhaust port is formed perpendicular to the suction port such that the compressed air introduced into the suction port forms vortices in the tubular body to separate heavy slurry from the compressed air by using a centrifugal force.
 3. The device of claim 2, wherein the tubular body is formed such that a diameter thereof becomes smaller downward, and a slurry storage box for storing the centrifugally separated slurry is provided at a lower portion of the tubular body. 